1. Field of the Invention
The present invention relates to a data storing device for writing or reading data in or out of a cylindrical or hollow cylindrical data storing medium.
2. Description of the Background Art
Generally, a hard disk drive or similar data storing device includes a disk and a head facing each other and rotates the disk while moving the head in the direction of tracks to thereby write or read data in or out of the disk. The disk is implemented as a magnetic disk or a magneto-optical disk. An optical pickup is used in the case of a magneto-optical disk.
The problem with the data storing device implemented as a disk is that the position of the head relative to the disk varies due to the vibration or the eccentricity of the disk surface, obstructing accurate data writing and data reading. In light of this, Japanese Patent Laid-Open Publication Nos. 64-51579, 6-60607 and 11-86507 disclose cylindrical or hollow cylindrical data storing media that replace the disk type data storing medium.
However, it is difficult even with a cylindrical or hollow cylindrical data storing medium to densely store data because the axis of rotation of the medium rotating at high speed vibrates when subjected to an impact or a shock. The data recording medium is apt to hit against the head when noticeably vibrating and be damaged thereby. Further, the cylindrical or hollow cylindrical data recording medium is connected to a drive motor via a rotary shaft and other transmitting parts, resulting in an increase in the number of parts. Moreover, even when dynamic-pressure fluid bearings exist in a rotation transmission path, the bearings themselves need a number of parts and make the entire data storing device sophisticated in structure.
It is an object of the present invention to provide a data storing device capable of density storing data in a cylindrical or hollow cylindrical data storing medium while making the most of the merits of such a data storing medium.
It is another object of the present invention to provide a data storing device capable of allowing a data storing medium to smoothly rotate with a minimum number of parts.
A data storing device of the present invention includes a cylindrical or hollow cylindrical data storing medium rotatable about its own axis and having a storage layer formed on its circumferential surface for storing data. A head adjoins the storage layer for writing or reading data in or out of the storage layer. A head moving mechanism causes the head to move back and forth along the axis of the data storing medium. A drive motor for driving the data storing medium includes a stator and a rotor spaced from the stator and directly coaxially connected to the medium.